Recently, there has been proposed a storage device which includes a high-resistance film between a metal film and a counter electrode. Metal ions, contained in the metal film, diffuse within the high-resistance film so as to form or eliminate filaments that contain the metal ions, thereby changing the electric resistance of the high-resistance film into either a lower or a higher resistance state. However, conventional storage devices of this type are typically not able to reliably retain the stored data in the high or low resistant states.